Highway crossing gate for railroads



June 20, 1944. w. K. HowE HIGHWAY CROSSING GATE FOR RAILROADS 5Sheets-Sheet 1` Filed May 27 1942 June 20, 1944. v W, K HQWE I VHIGHWAYCROSSING GATE FOR RILROADS Filed May 27, 1942 sheets-sheet' 2Flc-1.2.

- INVENToR y ATroRNY June 20, 1944.

w. K. Hows HIGHWAYI CROSSING GATE FOR RAILROADS Filed May 27, 1942 3sheets-sheet s co2 oo:

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Patented June 20, 1944 UNITEDY :STATES PATENTHQOFFICE HIGHWAYCRossINGfGATE Fon l RAILItoAns winth'rop'k. Howe, Rochester, N. Y.,assigner te General Railway Signal Company. Rochester,

Application May 27, 1942, Serial No. 444,689 i 7 claims.

. pounds and thus be costly to install and maintain. Furthermore, theweight may be so large and cumbersome as to swing so close to the groundwhen the gate is in the-vertical or clear position, as to be interferedwith by deep snows and the like and, hence function improperly underadverse conditions. j

With the above and other considerations in view, it is proposed inaccordance with this invention to employ a system of springs to replacethe usual counterweght, and thus provide a compact light-weight meansfor substantially counterweighting a crossing gate. This makes not onlyfor convenience and economyin handling and dependability in operation,but also makes for economy in the initial cost of equipment.

Since a single spring builds lup torque upon expansion or compression,at a rate diierent from that due .to the weight of the crossing gate, itis proposed to employ a spring system whereby its counterweightingeffect with respect to a gate will be substantially the same as that ofa counterweighting system employing a usual mass of iron or concrete asa counterweight.

vFurther objects, purposes and characteristic features of the inventionwill appear as the description progresses, reference being made.- to theaccompanying drawings showing, solely byway of example, and in no waywhatsoever in a limiting sense one form which the invention can In thedrawings- Fig. 1 is a fragmentary side sectional elevation atngvaluesand Ia series of curves, of a standard gate, and a' gate springcounterbalanced in accordance with this invention.

Fig. 5 is a diagrammatic view of the improved gate- I Referring now tothe drawings and iirst to Fig. 1,' there is here shown a gate pivoted toa supporting post and'operable by a motor or other suitable i primemover of vthewfgeneral type, for example, asfshown in the `patent to W.K. Howe, et al., No, 2,220,154, granted lNovember 5, 1940. A pole orpost P supports the gate, and to this post is fastened, by U-bolts orthe like, a housing comprising an upper 'portion or main housing MH, anda lower portion orspring housing SH, suitably interconnected by bolts I0or the like. Themain 'housing M H is closed by a cover C, removablyfastened to the vhousing as by bolts I I.

To facilitate assemblyas pointed Aout hereinafter,

the spring housing SH comprises two half cylindrical portions 61'andfIi2 fastened together with bolts I to form a. Cylindrical casingwhich has a bottom portion 8'fastened thereto as by hook bolts 9. Weldedto the side of this cylindrical casing at the Atop thereof are anglebrackets 36 through which pass the bolts I0 which connect this springhousing SH to the main housing MH.

Passing through theumain housing is a main shaft MS which is splinedthroughout its entire length and is suitably 'supported in the usualroller bearing assemblies I2 with the shaft extending beyond the housingto connect with an operating means, not shown, as at I3. Sleeved on themain shaft MS is a pair of brackets B which are connected to said shaftand constrained to turn therewith. These brackets are fastened by boltsor the like I4 to a frame member F of welded box-like formation to whichis suitably fastened the gate arm portions GA which are generally madeof Wood or like material.

It can thus be seen that upon rotation of the shaft, the brackets whichare constrained to rotate with theshaft operate the frame and the gatecarried thereby and, hence, the gate which is shown in Fig. 1 as beingin the horizontal or stop position can be moved to its vertical or clearposition by a rotation of the main shaft of substantially Carried on themain shaft and within housing MH is a crank arm CA which is constrainedto move with the shaft, as shown. AThis crank arm at its upper inner endis pivotally connected to a rod I6 which extends downwardly into thespring housing SH and passes through the convolutions of acounterbalancing spring CS which Il, which is itself threaded onitsouter'cylindrical face with a thread which screws into the spring CS.Nut l1 is held in positiorr'on the rod by a squaredfollowerfIryreceived"in aA squared socket in nut Il and keyed to the rodl5 by a key (not shown) receivedin the slot 1.81, and held therein bynuts I8, threaded cto'th rod i 6. The spring housing SH is now assembledaround the. spring CS and4 connected with the main housing'ashereinbeforef described; L l

With the construction' described Ajust "above, it is obvious thatth'eeffective' length Vof Ythe ccunterbalancing spring can be readilyadjusted by vscrewing the adjusting nut il into or out of thecounterbalahcing springand then iiiiing its position Vby, the''fllo'wer' Illyandnuts I8.y 'Ijhis adjustment permitswvarying theeffectivelength of the spring as just stated, andfhence Vpermits varyingthe rate of pile up o'f spring force as the spring is compressed."y

It is also possible with this construction to adjust the initiallortraped'-tension of the "counterbalancing spring. ,To'accomplish this itis merely necessary to slide the adjusting nut in one direction or thev'other without turning it within spring CS, and then xing its Ypositionby means of the follower andA nuts I0 and I8.

As shown in Fig. `1 ofthe drawings, the gate is positioned in thehorizontal or stop position and the crank arm CA is in the raisedposition whereby to have compressed the counterbalancing spring CS. Uponmoving the gate to the vertical or clear position crank arm'CA movesdownwardly and the spring -expands and supplies the major portion of thepower necessary to move the gate to its vertical position.

The horizontal position of the gate is determined by a stop spring SS,which is sleeved on a boss 2'I and is compressed by a head member 22adjustably carried on a threaded rod'23 which contacts with an adjustingstud A2li threaded into a stop lug SL, carriedon the crank arm, upon thegate reaching its horizon-tal position. With thisconstructionjit'canbefseen thattheinitial Y tension of stop spring SScanbe readily adjusted by means of the headmember 22, and its cooperatingnut`25, while the point at which the spring comes into play` can bereadily determined by means of stud 24in stop lug SL.

Ina manner similar to the stop spring SS for controlling the horizontalposition of the gate, there is a buffer spring BS (see Figs. 2 and 3)sleeved on a boss V2l and receiving a stud 28 vwith an adjustable head29 thereon for cooperating with an adjustable stud 30 carried in abuffer lug BL, constituting a portion of the cranky arm CA. 'When thegatereaches thefvertical position,

if it should tend to overrun slightly beyond this Y Y position, thebuffer spring comes into 'play to bui it and stop it. The gate arm islatched up in its verticalposition in the usual manner as, for example,(in the 'patentjreferredto above, and in this positirm,tllr'ebuifer'springl exerts no pressure on lthe "gate:

When the gate is raised to its vertical or clear position which isconsidered the 90 position, upon reaching about the position, a kick-offspring KS comes into play to, in effect increase the weight of the armand thus increase the tendency of the arm to move by vgravity to itsstop position. This kick-oir spring -KS is received on a boss 3l, and iscontrolled by a head 32 which is adjustable on a threaded stud 33 whichcan slide in a guide 34. As in the cases above, theinitial tension ofthis spring can be readily adjusted, as is obvious. The kick-off springis compressed by means of an adjustable stud 3 5 carried in a kick-olflug KL, constituting a part of the crank arm CA. When this stud 35contacts member 33, further movement of the gate compresses the kick-offspring and, hence, increases'the tendency of the gate to move to .itsVhorizontal or stop position.

It can be seen from Fig. 5,which is a diagram.- matic showing of thegate structure andoperating means, thatthe weight of the gate,multiplied by its lever arm, gives vthe value of torque ina downwarddirection, and this varies at-all points since the length ofthe leverarm so varies. On the other hand, the counterbalancing spring iscompressed to a `greaterfand greater extent, as the gate arm moves tothe horizontal position, vand thus the spring force varies. In thislcase, the lever arm through which the spring operates also varies sothat the gate torque and the counterbalancing spring torque do notfollow the same curve or, in other words, do not parallel each other.When the gate reachesits vertical or clear position, thecounterbalancingg'spring torque tends to approach the gate torque, andleave very little resulting net downwardor stop torque. If this were notrectied under."` conditions of high wind, in a given direction, theggatemight lfail to move by gravity to its stop position when 'unlatchedrIocorrect this situation, and rectify this fault, the kick-off springKS comes -in-to oper-ation between the 4'10" and the `90 or -clearposition to offset some of the effect of thecounterb'alancingA 4springCS and give a net downward stopfproducing torque at the `position,sufcie'nltto insure that the gate under all conditions will-certainlymove to stop position when unlatched.

In Fig. y4 is shown a table including aseries of torque values, sta-tedYin foot pounds, afseries of corresponding vspring pressures, a seriesoflever arm lengths, vin feet, and a -series of correspond- -ing degreesof -arm movement at whichfthey-.occur. It can be seen that the leverarm,"through which the counterbalancing spring operaztesfde- .pends uponthe position of the crank;.:arm CA andras shown in Fig. 5, this crankarm'm'oves from ra position Yd0 above the horizontal when'the gate armis horizontal to a position. 50 below the "horizontal when the-gate varmis vertical.-

Turning lto Fig. 4A the various curves -here shown are largelyself-explanatory. The curves in solid line are curves of torque lin footpounjds, plotted against; gate arm angularposition, ,which torque isexerted in -a downward Aor Istopproducing direct-ion of the gate. Thecurves in dash-and dot and dash lines represent foot pounds, of torque,plotted as before, but which lturques are exerted in an upwardolf-clearing direction of the gate.

The curve GAT shows the torque at various positions of the gate, whichis produced by the weight-of the .gate and, hence, is the .gatefarmtorque', arid'is' exerted downwardly. "There is -no asta-stair;

' counterweight employedwith this gate, but the.

operative' 'characteristics loff .such fa counterweighted fgate isconsidered 1 substantially ideal and, hence, thel'curve-CWT-isshown indot-and dashflinesl and is the upwardtorquewhichis produced byfa usualproperly proportioned counterweight. "The diierence at all points ofmovement of'the arm between these two curves'is the ynet resulting'downward torque which. is considered ideal 'and which vis-shown'by thecurve NWST or net weight stop torque.

In this Figure 4A is shown in dash line the torque curve of thecounterbalancing spring CS designated as CST, or counterbalancing springtorque and is a torque tending to clear the gate. A curve KST kick-offspring torque starting at the 70 position, and running to the 90position, is shown in full lines since this torque exerted by thekick-off spring is a downward torque tending to move the gate to thestop position. If this curve KST is combined with the curve GAT and fromthe resultant is subtracted the curve CST, a resulting curve which isthe net spring stop torque is obtained. This is shown in solid lines asNSST, and starts at the zero position somewhat above the ideal netweight down torque curve NWST, then passes below the ideal, and thenabove it, to pass below it at the 70 point, and then due to the elect ofthe kick-olf spring, passes up slightly above the ideal. If the kickoispring were not employed, this resulting down torque when the gate iscounterbalanced by a spring would follow the dotted portion of the curveNCSST, that is, net counterbalancing spring stop torque, and at the 90position would be too small to insure the certain movement of the gateto the stop position upon being unlatched. It can be noted that theresulting net spring stop torque, the curve NSST, closely approximatesthe resulting net weight stop torque which is obtained with the usualcounterweight, that is, curve NWST.

It can be realized from the above that the present arrangement andconstruction provides a cheaper, more dependable, and less cumbersomecounterbalancing means than can be realized with a counterweight of theusual construction. Furthermore, the net stop producing torquethroughout the entire range of operation of the gate, so closelyapproximates the ideal, that it is itself ideal. Thus, the fulladvantage of the usual counterweight is secured without any of its manydisadvantages.

The table comprising a portion of Fig. 4, gives various values andvarious positions of the gate which are used to plot various of thecurves described above. The derivation of the curve CWT counterweighttorque, and of the curve NWST, net weight stop torque, is not gone intoin detail in this disclosure since this is recognized as standardpractice by those skilled in the art and hence, readily understandable.

The above rather specic description of one form which this invention canassume is given solely by way of example and is not intended, in anymanner whatsoever, in a limiting sense. It is obvious that variousmodifications and adaptations can be made from time to time, as they mayappear expedient, without thereby departing from the scope and thespirit of this disclosure, except insofar as it is limited by areasonable construction of the appended claims.

Having described my invention, I now claim:

1. In a crossing gate for railways, in combination, an elongated gatepivoted near one of its ends andf'movable from ahorizontal stopyposition to a, vertical clear position, a; counterbalance spring, meansconnecting the gate tothe spring so as to progressivelydistortgthespring as the gatemoves-from its clear to its top position,and a sefcond` spring operatively associated with the gate so as vtobeprogressively `distorted as the tion, to a vertical clear position, ahelical coun terbalancing spring, means connecting the gate to thespring so as to progressively compress the spring throughout its entiretravel as the gate moves from its clear to its stop position, whereby tooppose gravitational effect on the gate'and a second helical springoperatively associated with the gate so as to be progressivelycompressed as the gate elects its nal substantially 20 portion of travelfrom its stop to its clear position whereby to aid gravitationaly effecton the gate.

3. In a railway crossing gate, in combination, an elongated gate pivotedadjacent one of its ends and movable under the force of gravity from avertical clear position to a horizontal stop position, a helical spring,means operatively connecting the spring and gate so as to progressivelydistort the spring as the gate moves from its clear to its stopposition, and independently operative means for respectively andindependently adjusting the effective length of the spring and theamount of trapped tension in the spring.

4. In a railway crossing gate, in combination, an elongated gate pivotedadjacent one of its ends and movable under the force of gravity from avertical clear position to a horizontal stop position, a helical spring,means operatively connecting the spring and gate so as to progressivelycompress the spring as the gate moves from its clear to its stopposition, means operative for independently adjusting the eiectivelengthL of the spring and the amount of trapped tension in the spring,and a kick-off helical spring positioned to be progressively compressedby the gate as it moves its last substantially 20 of its travel towardits clear position.

5. In a railway crossing gate, in combination, an elongated gate pivotedadjacent one of its ends and movable under the force of gravity from avertical clear position to a horizontal stop position, a helical spring,means operatively connecting the spring and gate so as to progressivelycompress the spring as the gate moves from its clear to its stopposition, a kick-off helical spring positioned to be progressivelycompressed by the gate as it moves its last substantially 20 of itstravel toward its clear position, and means to adjust the amount oftravel over which the gate compresses the kick-off spring.

6. In a railway crossing gate, in combination, an elongated gate pivotedadjacent one of its ends and movable under the force of gravity from avertical clear position to a horizontal stop position, a helical spring,means operatively connecting the spring and gate so as to progressivelydistort the spring as the gate moves from its clear to its stopposition, means operative for independently adjusting the effectivelength of the spring, and the initial tension in the spring, comprising,a rod passing through the coils of the spring, a nut slidably receivedon the rod and threaded to screw onto the convolutions of the spring,and adjusting means for the nut.

ing the springend gate sonas to progressively distort the springfas thegate moves the. entire distance from its clear. to its stop position;vand means `for independently adjusting the eiective length lof thespring and thevinitial tension inthe, x0

spring, comprising,.'a.;rod; passing through the ooils of the spring.,an,4 nut Asiidablyy received; on thev rod and threaded: on its-outerfacente screw into the*- com'Olautioitzs -V ofv 1 the spring, adjustingmeans forv thenutinc 1uding asquared Isocket in the nut. asquaredmatching follower"slidableA on the roda andv receivable; in the,ysocket, amd' lock nuts threadedfon the rod for bearing, againstl andbackngup the:iolloxvveiml v v K. HOW-E.

